Sheet conveying device and image forming apparatus incorporating the sheet conveying device

Abstract

A sheet conveying device includes a corrector configured to correct a position of a sheet, and at least three detectors disposed in a sheet conveyance direction. Each of the at least three detectors is configured to detect a lateral end of the sheet according to a length of the sheet to be conveyed in the sheet conveyance direction. The corrector is configured to correct the position of the sheet based on detection results of each of the at least three detectors.

What is claimed is: 
     
       1. A sheet conveying device comprising:
 a corrector configured to correct a position of a sheet; and 
 at least three detectors disposed in a sheet conveyance direction, 
 each of the at least three detectors being configured to detect a lateral end of the sheet according to a length of the sheet to be conveyed in the sheet conveyance direction, 
 the corrector being configured to correct the position of the sheet based on detection results of the at least three detectors; 
 wherein the at least three detectors include:
 an upstream detector disposed upstream from the corrector in the sheet conveyance direction; 
 a first downstream detector disposed downstream from the corrector in the sheet conveyance direction; and 
 a second downstream detector disposed downstream from the corrector and the first downstream detector in the sheet conveyance direction, 
 
 wherein, when the sheet to be conveyed is relatively long in the sheet conveyance direction, the upstream detector and the second downstream detector detect the sheet and the corrector corrects the position of the sheet based on detection results of the upstream detector and the second downstream detector, and
 wherein, when the sheet to be conveyed is relatively short in the sheet conveyance direction, the first downstream detector and the second downstream detector detect the sheet and the corrector corrects the position of the sheet based on detection results of the first downstream detector and the second downstream detector. 
 
 
     
     
       2. The sheet conveying device according to  claim 1 ,
 wherein the second downstream detector is disposed extreme downstream of the at least three detectors in the sheet conveyance direction, 
 wherein at least the second downstream detector is configured to detect the sheet regardless of a size of the sheet to be conveyed, and 
 wherein the corrector is configured to correct the position of the sheet based on detection results including a detection result of the second downstream detector. 
 
     
     
       3. The sheet conveying device according to  claim 1 , further comprising another upstream detector disposed upstream from the upstream detector in the sheet conveyance direction,
 wherein said another upstream detector is configured to detect a lateral end of the sheet, 
 wherein the upstream detector and said another upstream detector are configured to detect the sheet and the corrector is configured to correct the position of the sheet based on detection results of the upstream detector and said another upstream detector, 
 wherein, when the sheet to be conveyed is relatively long in the sheet conveyance direction, the upstream detector and the second downstream detector detect the sheet and the corrector corrects the position of the sheet again based on detection results of the upstream detector and the second downstream detector, and 
 wherein, when the sheet to be conveyed is relatively short in the sheet conveyance direction, the first downstream detector and the second downstream detector detect the sheet and the corrector corrects the position of the sheet again based on detection results of the first downstream detector and the second downstream detector. 
 
     
     
       4. An image forming apparatus comprising:
 an image forming device configured to from an image on a sheet; and 
 the sheet conveying device according to  claim 1 . 
 
     
     
       5. The image forming apparatus according to  claim 4 ,
 wherein the second downstream detector is disposed extreme downstream of the at least three detectors in the sheet conveyance direction and upstream, in the sheet conveyance direction, from an image forming position at which the image forming device forms an image on the sheet.